1. Field of Invention
This patent application relates to termite control, specifically to a method and system for termite interception and baiting designed to suppress or eradicate colonies of termites, thereby protecting objects such as structures, agricultural crops and trees against termite attack.
2. The Prior Art
For many years, the indiscriminate application of environmentally persistent pesticides at ground level in and around the foundation of structures at points of possible termite entry and attack, in order to form a barrier to termite entry, has been the only viable method for effective, long term protection of structures and other items against termite attack. However, concerns over the effect of such tactics on the short and long-term health of persons occupying treated structures and on the general environment surrounding the structures has forced a reassessment of termite control tactics by the termite control industry. This reassessment has included efforts to develop viable, low impact alternatives to indiscriminate "wholesale" applications of pesticides currently used to prevent or control termite attack.
One potential replacement method for barrier treatments for termite control is termite baiting. Termite baiting is the aggregation of termites at a fixed point and their elimination due to their consumption of a toxicant-containing bait placed at the point of aggregation. This method of protection has several advantages over current methods. It involves the use of only a fraction of the amount of pesticide active ingredient that would have been expended to accomplish protection of an object, such as a structure, using barrier methods. The pesticide bait can optionally be placed in a secured, tamperproof station that prevents movement of bait out of the station into the general environment, yet permits termite entry into the station. Placement of bait in a station also minimizes the potential for exposure of humans, especially children, and large animals to the bait. Perhaps most importantly, termite baiting results in the elimination or suppression of the termite colony, not just the exclusion of members of the colony from the point of attack or object being protected. Because a termite bait must be consumed by termites in order to be effective, a technique must be developed to consistently and repeatedly make the bait available for consumption by members of a termite colony at a fixed point over a long enough period of time for the bait to have the intended toxic effect on the colony. However, to accomplish this, a baiting system must deal with several issues that left unresolved, make a baiting method and/or system unlikely to succeed.
Because termites consume cellulose for nutrition, termites are a serious threat throughout much of the world to structures or other objects containing wood or other cellulose containing components. Termites can be divided into two basic classifications, subterranean and non-subterranean. Subterranean termite colonies live primarily in the ground and forage for cellulose containing food items in the earth or above ground by building a system of closed mud tunnels to traverse from the ground to the above ground food source. Non-subterranean termite colonies live above ground near or within the food source they are consuming.
For several reasons, it is desirable that termite bait be applied only after contact has been established with a termite colony and termites are aggregated for the purpose of feeding on the bait at a fixed, arbitrary baiting point. These reasons include minimization of the amount of bait manufactured, potential deterioration of bait if it is left in place for long periods of time in anticipation of prospective termite attack, minimization of the potential for unintended exposure of children and pets to the bait, etc. Therefore, any responsible baiting method and/or system must anticipate the need to first aggregate termites at a point with a nontoxic aggregating medium and only then apply toxic bait at that point.
As currently developed, bait stations are devised to achieve detection and suppression of termites by utilizing a system comprised of a housing with openings and a set of interchangeable bait cartridges. In the device described in U.S. Pat. No. 5,329,726, granted Jul. 19, 1994, the architecture of the cartridges is such that they have a plurality of openings that correspond to the openings in the housing when placed within the housing.
The problem of termite disturbance is addressed in U.S. Pat. No. 5,329,726 by providing that the cartridges used for identification and suppression of termites each have openings that align with the housing openings when the cartridges are inserted within the housing. After detection of termites in nontoxic bait cartridge used during the detection stage, that cartridge is removed and replaced with a toxic bait cartridge of corresponding architecture. In accordance with the teaching of patentee in U.S. Pat. No. 5,329,726, the substitution of the pesticide containing cartridge for the nontoxic cartridge will not disturb pre-existing galleries or passageways established by termites to provide access between the termite colony and the openings in the outer housing of the control station because the outer housing remains fixed relative to the terrain and the openings in the pesticide cartridge remain in alignment with the openings in the housing. Accordingly, termites are provided with continued access to the pesticide-containing bait cartridge within the housing, thus permitting continuous feeding and the transport of pesticide-containing food to the termite colony through the pre-established connections between the colony and the bait stations.
3. The Present Invention
In accordance with the present invention, a system has been devised which allows termite detection and baiting in a manner where the transition of feeding termites from nontoxic to toxic bait is effected with minimal, if any, disturbance of the nontoxic bait feeding site.
Instead of removing the nontoxic bait that aggregated the termites at the baiting point and replacing it with toxic bait as taught in U.S. Pat. No. 5,329,726, the present invention leaves the nontoxic bait in place and supplements it with toxic bait placed adjacent to the nontoxic bait that is infested with foraging termites. Although, U.S. Pat. No. 5,329,726 teaches that disturbance of termites is minimized by the use of an interchangeable system of cartridges, such a system of cartridges does not minimize the disturbance of foraging termites to the same extent as the present invention. This is because a system of interchangeable cartridges, while not disturbing termite tunnels up to the point they enter the outer housing, does disrupt and sever, during cartridge substitution, the termite tunnels that have been constructed by termites between the inner wall of the outer housing and the maximum point to which they have penetrated the cartridge of nontoxic bait; it being possible that termites disturbed even to this extent by the changing of cartridges can abandon a baiting site on account of such disturbance, thereby negating any opportunity to eradicate the colony. Additionally, according to the teaching of U.S. Pat. No. 5,329,726, termites are forced to involuntarily transfer from infesting and consuming nontoxic bait to consuming toxic bait whereas according to the present invention, termites can voluntarily transfer from consuming the nontoxic bait to consuming the toxic bait. The present invention, because it never disturbs or removes nontoxic bait or toxic bait infested with termites, avoids the disturbances inherent in the use of a system of interchangeable cartridges.
This is achieved by utilizing an architecture of housing and interceptor (the nontoxic bait element) wherein the interceptor is fixedly attached within or without housing in a manner which allows the introduction of toxic bait into the housing while minimizing disturbance of the interceptor that termites are feeding on. By minimizing disturbance of the feeding termites the likelihood of termites abandoning the site is greatly reduced.
A key feature of the present invention resides in introduction of bait in a manner which does not disturb the nontoxic bait sites and access to and from same.
Reference to the architecture of housing and interceptor developed in accordance with the present invention utilizes interceptor placement outside and/or inside the housing into which the toxic bait is introduced. Indeed, in one of the embodiments of the invention, the interceptor forms a gateway to the housing interior. In the embodiment where the housing is sealed to eliminate access by other termite competitors and/or predators, access to the interior volume of the housing is achieved by consuming the portion of the interceptor which covers the housing opening/openings fabricated as termite access ports.
Referring, by way of example, to the system devised in which the nontoxic bait used during the termite detection stage is fixed within or without a perforated housing and entirely covers the openings in the perforated housing, it is notable that both the housing and the nontoxic bait remain fixed relative to the terrain in which they are placed and the entrance through the housing as well as the nontoxic bait remain undisturbed in the course of introduction of toxic bait after the presence of termites is detected.
In describing the present invention herein, the nontoxic bait which is affixed to the sidewalls is referred to as an interceptor. The presence of termites is identified when consumption of the nontoxic bait interceptor or exploratory tunnels formed by termites is observed by looking into the housing. Importantly, in accordance with the present invention, after detection of termites, the integrity of the passageway or tunnel constructed by termites through the housing wall and in, on, through and/or around the nontoxic bait interceptor is not disturbed.
Further, in accordance with the present invention, the toxic bait is introduced into the interior of the housing and as the termites consume the toxic bait, it is replenished--again without disturbing the integrity of the passageways through the previously placed bait or disturbing any part of the interceptor that has not been consumed. Moreover, in accordance with a specific embodiment of the present invention, by compartmentalizing the housing interior to form a plurality of compartments which termites can access once they have entered the housing interior, such as by utilizing dividing walls with openings through which termites can pass from one compartment to another, toxic bait can be introduced sequentially in each compartment. Thus, as the toxic bait introduced into one compartment is consumed, toxic bait can be introduced into another compartment thereby even avoiding the de minibus disturbance of the nontoxic bait interceptor and the toxic bait residue being replenished.
Yet further in accordance with the present invention, provision is also made for excluding nontarget insects from the baiting site delimited by the housing. The presence of such nontarget organisms such as ants, which are natural enemies of termites, is avoided by allowing access to the interior of the housing only through openings leading thereto formed by the termites themselves.
The architecture of the baiting system of the present invention provides a bait station system and method for termite detection and control that minimizes disturbance to pheromone trails laid down through, around and within the bait housing at all stages of use, namely, identification, introduction of toxic bait and supplementation of toxic bait as the toxic bait is consumed.
The present invention allows termites to be successfully transitioned from consuming the nontoxic substance that aggregated them to consuming the toxic bait that will suppress or eliminate them while minimizing disturbance of the feeding termites. Moreover, in accordance with the present invention, if a placement of toxic bait is consumed before colony suppression or elimination is completed, termites are transitioned from consuming one batch of toxic bait to consuming another batch of toxic bait while minimizing disturbance of the feeding termites. Therefore, the method and system disclosed herein operate on the underlying principle that as part of the baiting process, termites must be successfully transitioned from consuming a nontoxic aggregating medium to consuming a toxic bait or transitioned from consuming one batch of toxic bait to consuming another batch of toxic bait without disturbance or at least in a manner minimizing disturbance.